A CRITICAL STUDY ON DIMENSIONING OF HYDRO POWER STATIONS WITH PELTON TURBINE

Abstract

The hydro turbines convert the potential energy into mechanical energy for its further conversion into electrical energy by use of electrical generators. In a hydro power station, the hydraulic turbine is the centre, or in other words the heart, as all the dimensional parameters are dependent upon its dimensions. Therefore, during the planning stage, the dimensioning of the hydro power plant begins with the selection and sizing of the hydro turbine. Project planning involves proper analysis of stream flow and waterpower studies, reservoir levels, location, foundation conditions, determination of capacity, number and size of units and layout and dimensioning of hydro power station. The estimates of cost much depend upon the preliminary planning which determines the scope of the project and forms the basis for judgment of its feasibility and for authorization of the expenditure of the funds required. After such authorization the final design and construction will necessarily follow closely along the lines of the general plan in order to remain within the limits of the estimated cost. As the hydropower stations have very costly electro-mechanical equipments and civil structures therefore it is essential to be extremely careful about its dimensioning and layout. Power studies preceding the preliminary dimensioning and design of hydro power stations will generally furnish information on the maximum and minimum heads prevailing at the site under consideration, average head during a period of low stream flow and desirable total installed capacity at the station. At this early stage of the planning, multiplicity of the possibilities of different combinations of numbers and size of units are to be studied. At such crucial stage, preliminary dimensioning of hydro power station is to be carried out based upon the experiences of previous installations of hydro •., . power projects. It is imperative that the preliminary dimensioning of the power station should be made in such a manner that requirements can be met by the manufacturers without much deviation. The selection of the turbines in the overlapping range of Pelton and Francis turbines through the comparion of installations of different capacity and head has also been done IX to delineate head ranges governing specific type of turbine, viz. Pelton or Francis, can be used. As there is no IS code available for the preliminary dimensioning of hydropower station with Pelton turbine, the present work is an effort to develop and present certain useful guidelines and develop a set of relationships for the Dimensioning of Hydropower Stations with Pelton Turbine as in the case of reaction turbines. For this purpose, work done by De Sievro and Lugarsi, on the Modern Trends in Selecting and Dimensiohing of Hydropower_ Station with Pelton Turbine [5], has been extended by collecting data of power stations with Pelton Turbine in India and have been analyzed to reach at the conclusion.